Treatment of fabric



. agents.

Patented Oct. 25, 1932 cmmm nnnxrus, or new YORK, n. Y.,

AND HERBERT PLATE, CUMBERLAND,

MARYLAND, ASBIGNORS TO CELANESE CORPORATION OF AMERICA, A CORPORATION 01 DELAWARE No Drawing. Application aled June 27,

This invention relates to the treatment of yarns or fabrics containing organic esters of cellulose and particularly cellulose acetate with a bath containing an alkaline agent, whereby the fabric may be treated with cotton dyes, and other of its properties improved.

An object of our invention is to treat yarns or fabrics containing organic esters of cellulose withan alkaline solution in such a manner that the yarn or fabric may be dyed with cotton dyes in a satisfactory manner. Another object of our invention is to treat yarns or fabrics containing cellulose acetate with alkali solutions of sufficient concentration and in such manner that the same may be dyed with dischargeable colors, whereby discharge prints may be produced on such fabrics.

The discharge printing of fabric containing organic derivatives of cellulose and particularly cellulose acetate to produce light fi res on dark backgrounds has heretofore 0 ered serious difiiculties. This is due to the fact that the dark colors, such as reds, blues and blacks that are available for the dyeing of cellulose acetate fabrics cannot be discharged by pastes containing ordinary color discharging agents. We have discovered that if fabrics containing cellulose acetate yarns are treated with an alkaline bath under the conditions set forth below, a fabricis produced which is capable of being dyed with dyes thatmay be discharged by printing pastes containing. ordinary discharging Moreover the fabric, when treated by our process, has further desirable properties, such as having its safe ironing point materially increased.

In accordance with our invention, we treat fabrics or yarns made of or containing organic esters of cellulose with a'saponifying bath containing an alkaline solution of comparatively high concentration, preferably at low temperatures. The fabricmay then be dyed with suitable dyes and if desired, the dyed fabric may then be printed with a discharge paste which contains a .reducin agent, with or without colors, and the printe hydroxide or ramrmnnr or name 192s. Serial No. 288,805.

fabric may th en be steamed and further treated in any suitable manner.

The fabric to be treated by our invention may contain yarns of any suitable organic ester of cellulose such as cellulose acetate, cellulose formate, cellulose propionate or cellulose butyrate. The fabric may consist wholly of yarns made of one or more of these organic esters of cellulose, or it may be a mixed fabric containing yarns of these organic esters of cellulose and the, yarns of other fibers. Examples of such mixed fabrics are mixed cellulose acetate and cotton, and mixed cellulose acetate and silk.

The saponifying bath may contain any suitable alkali and is preferabl of comparatively high concentration. Of t e alkalis that are suitable, sodium hydroxide, potassium ammonia may be mentioned. The concentration of the alkali solution is preferably from 5 to 20% by weight. We have found that the use of caustic soda solution is suitable for. causing the cellulose acetate fabric to take direct cotton d es in a satisfactory manner. However, if it also desired to increase the safe ironing temperature, a caustic soda solution is preferred, since by the use of this solution the safe ironing temperature of a cellulose acetate fabric is mcreased' from 220 C. to 260 G. However, no advanta e from the dyeing point of View is obtained fiy using a caustic soda solution of-greater than 10% concentration. The saponifying bath may also contain such assistants as alcohols, sodium acetate, etc.

The alkali solution may be applied to the fabric containing the organic esters of cellulose in any suitable manner. However, we

refer to apply the caustic soda to the fabric y padding the caustic solution ontothe fab no and then permitting the same to stand for an appreciable length of time as will be described below. The temperature of treatment is preferably room temperature 'and should nolf exceed C: for obtaining the best resu ts.

The fabric after it has been treated-with the saponifying bath, as above indicated, is capable of being d ed by dyestuffs that have an aflinity for cel ulose acetate but not for cotton, such as are known as SBA dyes, and also by dfves that have an afinity for cotton but not or cellulose acetate, such as direct cotton dyes. The direct cotton colors available for dyeing this material are within all ranges of colors. These cotton dyes include blues, blacks and reds, which may be discharged by ordinax discharge printi astes, and therefore 'scharge prints of dar ackgrounds may be produced on this fabric, a result heretofore notattainable on fabrics containin cellulose acetate am.

The fa ric, so treated an after having been adiyed with direct cotton dyes, may be print with a discharge paste which contains a reducing agent and which ma or may not contain colors for rinting the discharge portions. After printing with the discharge paste, the fabric is steamed and given other treatments as is well understood in the art.

The discharge paste may be applied in any suitable manner such as by means of engraved or embossed rolls, plates or blocks. The paste may also be applied through stencils by means of brushing or spraying. charge paste may contain an ing agent such as sodium ydrosulphite or zinc hydrosulphite or the su stances known as protolin which is sulphoxalate of zinc formaldehyde. For obtainin a white backound the sodium hydrosu hite or zinc ydrosul hite are referred, w ereas if a colored disc arge is 'esired the protolin is preferred.

In order to further illustrate our invention the following specific example is given.

Example A fabric consistin wholl acetate yarn is padd throng rolls that are covered with several thicknesses of heavy cotton lapping or other absorbent materia using a bath containing 100 parts of water and 10 parts of'caustic soda. The caustic soda solution is at room temperature, and the fabric is given two runs through the gad. The nip on the pad is arranged so that t e fabric picks up an amount of solution equal to its own weight. After the second run on the pad, the roll of fabric is allowed to run 15 minutes, and the solution is then very li htly extracted on the roll. The fabric wit the remaining solution is allowed to stand overni ht at room temperature. In carr in out this process, itis im rtant to give us eed to the strength of t e caustic soda solution and to the temperature of treatment, which should not exceed 35 C. Likewise it is of imsprtanoe that the fabric should be batched wi a minimum amount of tension and that the caustic soda solution should be allowed to remain on the fabric for a period comparable to that of overnight. After standing overni rinsed in water and is re y for dyeing. Of

The dis-. suitable reducof cellulose ht, the fabric is Leases:

the direct cotton dyes that may be used, the followin are suitable for a ight fastness equal to 5 hours in the fadeometer.

National solantine blue 4-GL Pontamine fast black CW (Color Index 539) Pontamine yellow CH (Color Index 365) Newport direct fast red F (Color Index 419) Amanil black BOL (American Aniline Prod. Co.) (Color Index No. 493

Newport light fast blue S Chlorantine fast blue RL (Ciba) (see Color Index Supp. (page 31) Chlorantine fast blue 8- L (Ciba) (see Color Index Supp. page 31).

If a diazotized and developed d e is desired, diamino no extra (General yestufis Corp); (Color ndex 317 or diazo fast n BL eneral estufls orp.) (Color ndex No. 532) may applied to the fabric and the same then diazotizedand developed with beta naghthol.

For 0 taining a navy color of cod fastness to light hours fadeomcter) t e following mixture may be used:

National solantine blue 4 GL Pontamine block CW (Color Index 539) Pontamine yellow CH (Color Index 365) Newport direct fast red F (Color Index 419) For a navy of modern fastness to light the following mixtures of dyes may be used:

Diazine black H extra (Color Index No. 401) Chlorazol sky blue FF (Color Index No. 518 Pontamine yellow CH (Color Index No. 365) Newport .fast scarlet 4-BA (Color Index 326) Parts Gum tragacanth 1/12 100 Protolin 40 Water 40 This aste is most suitable for obtaining colore discharges. If a white discharge is desired the rotolin is replaced by a hydrosulphite,suc asformalde yde hydrosul bite or sodium hydrosulphite and any sired color is added to the paste. The fabric after printing is dried and steamed and then' finished in any desired manner.

It is to be understood that the foregoing details are given merely by tion and that many variations may be made therein without departing from the spirit of this invention.

Havin described our invention what we claim an desire to secure by Letters Patent 1. Method of treating fabric containing suitab e de-.

way of illustraaseaaaa organic esters of cellulose comprising paddingthe fabric with an alkaline solution corresponding to a caustic soda solution of a concentration of from 5to 20% at a temperature below 35 (1, in the absence of retarding agents, batching the fabric containin the alkaline solution for 8 to 14 hours an then removing the alkaline solution.

2. Method of treating fabric containing cellulose acetate comprising padding the fabrio with an alkaline solution corresponding to a caustic soda solution of a concentration of from 5 to 20% at a temperature below 35 0., in the absence of retarding agents batching the fabric containing the alkaline solution for 8 to 14 hours and then removing the alkaline solution. 1

3. Method of treating fabric containing organic esters of cellulose comprising padding the fabric with an alkaline solutioncorresponding to a caustic soda solution of a concentration of about 15% at a temperature be- 7 low 35 (3., in the absence of retardin agents, batching the fabric containing the alkaline solution for 8 to 14 hours and then removing the alkaline solution.

4. Method of treating fabric containing cellulose acetate comprising padding the fab ric with an alkaline solution corresponding to a caustic soda solution of a concentration of about 15% at a temperature below 35 (3., in the absence of retarding agents, batching the fabriccontaining the alkaline solution for 8 to 1% hours and then removing the alkaline solution.

5. Method of altering the dyeing properties of a fabric containing yarns of cellulose acetate comprising padding the fabric with an alkaline solution corresponding to a caustic soda solution or 5 to 20% concentration at a temperature below 35 C. in such amanner that the fabric takes up substantially its own I Weight of alkaline solution, in the absence of retarding agents, batching the fabric containing the alkaline solution for 8 to i l hours at said temperatures and then removing the alkaline solution.

6. Method of altering the dyeing properties oi a fabric containing yarns of cellulose acetate comprising padding the fabric with an alkaline solution corresponding to a caustic soda solution of about 15% concentration at a temperature below 35 C. in such a mannor that the fabric takes up substantially its own Weight of alkaline solution, in the absence of retarding agents; batching the iabric containing the alkaline solution ior 8 to 14 hours at said temperatures and then removing the alkaline solution.

In testimony whereof, We have hereunto subscribed our names. A

CAMILLE DEEYFUS. 

